<style type="text/css">
.container {
    background-color: yellow;
    /* border: 5px solid darkred;*/
    /*padding: 20px;*/
    margin: 30px;
}

.box1
{
    background-color: lightgreen;
    height: 100px;
    border: 5px solid darkgreen;
    padding: 20px;
    margin: 40px;
}

.box2
{
    background-color: lightblue;
    height: 100px;
    /*border: 5px solid darkblue;
    padding: 20px;*/
    margin: 50px;
}

.box21
{
    background-color: lightcoral;
    height: 100px;
    /*border: 5px solid darkblue;*/
    /*padding: 20px;*/
    margin: 100px;
}

.box3
{
    background-color: lightcyan;
    height: 100px;
    border: 5px solid darkcyan;
    padding: 20px;
    margin: 60px;
}

.float-box-left
{
    float: left;
    width: 80px;
    height: 80px;
    border: 5px solid darkred;
    background-color: lightsteelblue;
}

.float-box-right
{
    float: right;
    width: 80px;
    height: 80px;
    border: 5px solid darkred;
    background-color: lightsteelblue;
}

.clear
{
    clear: both;
    height: 5px;
    background-color: red;
    margin: 10px;
}
</style>
<div class="container">
    <div class="float-box-left"></div>
    <div class="clear"></div>
    <div class="box1"></div>
    <div class="box3"></div>
</div>
